| Project/Area Number |
17540268
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | Waseda University |
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Principal Investigator |
MAEDA Kei-ichi Waseda University, Physics Department, Professor (70199610)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2006: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | cosmology / brane gravity / dark energy / string theory / general relativity / cosmological constant / black hole / inflation |
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| Research Abstract |
New idea of gravitation is given from a "brane" in string theory, and it has recently been intensively studied because it may lead to new paradigm of cosmology. In the present research project, we have analyzed systematically fundamental problems in cosmology from the view point of a brane world in order to study new subjects such as what is the fundamental and important in brane gravity or what will be new paradigm of brane cosmology. Especially, studying new gravitational theory with a brane, we have discussed most important subjects in cosmology such as "dark energy", "cosmological constant problem", "creation of the universe" and "cosmological singularity". We have analyzed mainly the following three subjects:
(1) The study of the unconventional early universe models based on brane collision
Taking into account self-gravity, we have analyzed a brane collision and shown that a spacetime singularity is formed because of gravitational instability. We have also studied the possibility of creation of matter (the origin of matter) in the universe via a brane collision.
(2) The study of the inflation models based on string theory
We have proposed new inflationary model based on string theory. We have studied the higher curvature terms which appear via quatum corrections in superstring theory. Although we find sufficient expansion of the universe, we need a fine tuning of initial conditions. It suggests that we have to find the proper correction terms with the Ricci curvature tensor as well as the Riemann one.
(3) The construction of black hole solutions based on string theory
We have presented new method to find black hole solutions in string theory. It is generalization of the conventional method using the BPS equations. We have obtained a new black hole (a caged black hole) solution.
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